1. Field of the Invention
The present invention relates to apparatus and a method of recording and translating data utilizing a recording medium. More particularly the present invention relates to a method of sequentially spacing data points on a recording medium such that the distance between data points is indicative of the quantitative level of each event. This method is particularly useful for field installed monitoring equipment.
2. Description of the Prior Art
Conventionsl monitoring equipment as is presently commercially available is severely limited in the amount of data that can be recorded over a time period. Available equipment using a Westinghouse WR4C recorder is limited to recording three data inputs on a four channel magnetic tape. One channel records time and a single data input is recorded on each of the other three channels. The present invention provides apparatus and a method for sequentially recording multiple data inputs on a single tape channel.
Many applications for monitoring equipment require upwards of 15 to 20 variables be recorded during a monitoring period. Utilizing commercially available equipment, seven separate recorders each having three data inputs would be necessary to monitor all 20 variable. Using multiple recorders necessitates expensive capital expenditures and presents problems with processing and correlating multiple tapes.
A separate patent application entitled "Double Time Sequenced Multiplexing Method of Recording and Translating Data," Ser. No. 854,180, filed simultaneously herewith discloses a method of multiplexing data on a single channel of magnetic tape. Therein the method disclosed requires that the distance between a base point and an event point be determined to ascertain the quantitative level of each event. Furthermore a base clock is used to generate the base point.
The method and apparatus herein does not use a base clock or generate base points. The quantitative level of each event herein is ascertained from the distance on the tape between successive event points. The elimination of the base point allows much more information to be stored on a given length of tape. The elimination of the base point further serves to increase the reliability of the monitoring system since only half as many points need to be applied to the tape and subsequently detected.
The air conditioning and refrigeration industry as part of a continuing effort to improve quality and reliability of equipment has developed testing techniques involving monitoring equipment in the field. With the current awareness for energy conservation it has become particularly important to develop and monitor high efficiency heat pump units.
The various factors which might typically be measured for a heat pump installation include: power to the structure, power to the outdoor fan, power to the compressor, power to the indoor fan, compressor cycles, compressor run time, supplemental resistance heat on time, supplemental resistance heat cycles, defrost cycles, total defrost on time, length of each defrost cycle, time of each defrost cycle, indoor temperature, outdoor temperature, supply air temperature, return air temperature, indoor relative humidity, outdoor relative humidity, supply air flow, system capacity, barometric pressure, wind speed and wind direction.
The method of recording and translating data herein involves multiplexing information sequentially on a single channel of a recorder without the necessity of a separate time channel. Most or all of the above events could periodically be recorded on a single tape channel using the herein described method.